[swift-evolution] generic associatedtype?

[Jens Persson]

Has there been any discussions about the possibility of having generic
associatedtypes?

I (naively) think that it would open up a lot of possibilities.
Because if, for example, we could do this:

protocol CountType {
    associatedtype Storage<E>
    ...
}

Then we could do this:

struct Count1 : CountType {
    typealias Storage<E> = (E)
    ...
}
struct Count2 : CountType {
    typealias Storage<E> = (E, E)
    ...
}
struct Count3 : CountType {
    typealias Storage<E> = (E, E, E)
    ...
}
...
protocol StaticArrayType {
    associatedtype Count: CountType
    associatedtype Element
    ...
}
struct StaticArray<C: CountType, Element> : StaticArrayType {
    typealias Count = C
    var storage: C.Storage<Element>
    ...
}



Would adding support for generic associatedtypes be possible? Are there any
plans for it?

(
I tried searching for it but I found only this:
https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20160411/015089.html
)

Thanks,
/Jens
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